Transformer apparatus cooling system



P. RADKOWSKI ET AL 3,371,299

TRANSFORMER APPARATUS COOLING SYSTEM Feb. 27, 1968 2 Sheets-Sheet 1 Filed Feb. 10. 1966 Feb. 27, 1968 P. RADKOWSKI ET AL 3,371,299

TRANSFORMER APPARATUS COOLING SYSTEM Filed Feb. 10, 1966 2 Sheets-Sheet 2 WITNESSES 2 f i g ATTORNEY United States Patent Ofiice 3,371,299 TRANSFORMER APPARATUS COOLING SYSTEM Paul Radkowski, Pulaski, and Leo Radkowski, Sharon, Pa., assignors to Westinghouse Electric Corporation, Pittsburgh, Pa., a corporation of Pennsylvania Filed Feb. 10, 1966, Ser. No. 526,623 5 Claims. (Cl. 336-57) This invention relates to power transformers of the core form type, and more particularly to an improved housing and cooling system for power transformers of the core form type.

It is an object of this invention to provide an improved power transformer of the core form type wherein the primary and secondary coils or windings of the transformer are concentric, and cooling fluid is circulated between the concentric coils or windings to provide cooling of the coils or windings.

It is another object of the present invention to provide an improved and lower cost housing for power transformers of the core form type.

It is another object of the present invention to provide an improved transformer of the core form type wherein definite ducts are provided for circulating cooling fluid from the top of the housing or casing back to the bottom of the housing or casing and up through the coils or windings of the transformer to provide cooling of the coils or windings.

It is also another object of the present invention to provide an improved transformer of the core form type wherein a manifold to which a cooling fluid is returned from the top of the transformer housing or casing to the bottom of the housing or casing also provides a bottom support for the transformer housing.

These and other objects are effected by this invention as will be apparent from the following description taken in accordance with the accompanying drawings, forming a part of this application, in which:

FIGURE 1 is a perspective view of a core form transformer constructed according to this invention, with parts broken away for the purpose of clarity; and

FIG. 2 is a cross sectional view of the transformer similar to the transformer illustrated in FIG. 1, with the exception that pumps are illustrated for circulating a cooling fluid.

In the prior art it has been the practice to construct power transformers of the core form type with concentric primary and secondary coils or windings. This type of transformer is usually cooled with some type of fluid coolant. In the prior art it has been the practice to circulate the hot cooling fluid from the top of the transformer housing through external coolers to cool the fluid and return the cooled fluid coolant to the bottom of the transformer housing. In order to make this cool fluid coolant recirculate up through the concentric windings to cool the windings it was necessary to provide extensive baffling in the bottom of the transformer tank. This bafliing was usually constructed from cellulosic pressboard. It has been found from prior experience that after extensive use that this baffling often became ineffective to direct the cooling fluid up through the concentric windings due to the deterioration of the pressboard with age. This method of directing the cool cooling fluid up through the concentric windings was also expensive since the pressboard used has to be a good grade of electrical insulating cellulosic material which meant that the material was expensive and it also required extensive labor to properly construct the baffling during the assembly of the transformer.

This invention provides a transformer of the core form type having concentric cores or windings wherein an cf- 3,3 71,299 Patented Feb. 27, 1968 ficient cooling system is provided which eliminates the above pointed out objections to the prior art systems.

Referring to FIG. 1 in detail, a three-phase core form transformer 10 is illustrated. The transformer 10 includes a housing or casing 12 which is comprised of a top wall 14 through which low voltage bushings 16 and high voltage bushings 18 extend. The casing 12 also comprises two end walls 20, two side walls 22 and a bottom wall 24. The transformer 10 illustrated in FIG. 1 is a threephase power transformer and includes a laminated magnetic core having three winding legs 32 and two yoke portions 24 connecting the winding legs 32. A set of windings comprising concentric low voltage winding 36 and high voltage windings 38 are fitted over each of the winding legs 32 of the core 30. It is seen that the concentric windings 36 and 38 are spaced from each other to provide a duct 40 therebetween for circulating cooling fluid. The core is held in assembled relationship by means of two frame members 42 which are clamped to the top yoke member 34 by means of clamping bolts 44. The bottom yoke member of the core is clamped between two hollow manifold members 46 by means of bolts hollow members 46 in addition to serving as the lower frame members for holding the lower yoke portion 34 of the core 30 in assembled relationship; but, also, as will be pointed out hereinafter functions as manifolds for the return of the cool cooling fluid to the bottom of the transformer housing 12.

As seen in FIG. 1 a cooling fluid distribution ring 48 is placed between the upper ends of the windings 36 and 38 and the upper frame members 42. The cooling fluid distribution rings 48 have a series of openings 50 therein for evenly distributing the cooling fluid as it is forced up between the windings 36 and 38. It is also seen from FIG. 1 that a similar fluid distribution ring 52 is placed between the ends adjacent the bottom wall 24 of the housing or enclosure 12. However, between the ring 52 and the ends of the windings 36 and 38 there is positioned an oil distribution ring which comprises two con centric rings 54 and 56. The rings 54 and 56 have an opening 58 there'between which evenly distributes the cooling fluid as it starts up through the opening 40 between the windings 36 and 3-8. It is seen that the ring 52 has openings therein which correspond or match with openings 60 in thebottom wall 24 of the tank 12. These openings 60 in the bottom wall 24 of the tank 12 also match openings 62 in the top of each of the manifold members 46. The ends of the manifold members are closed by plates 64 which are attached thereto to provide a fluid tight connection between the ends of the manifold members 46 and the plates 64.

A metal plate member 66 is attached, by welding or some other means, to the bottom side of the two manifold members 46 to provide a smooth base support for the transformer 10. As seen from the description hereinbefore the manifold members 46 serve the dual purpose of providing frame members for holding the lower yoke portion 34 of the core 30 in assembled relationship and also provide a bottom support for the entire transformer 10 and provide means for returning the cooling fluid to the bottom of the transformer housing and directing the cooling fluid up through the opening 40 between the concentric windings 36 and 38 to efliciently cool the windings of the transformer. With this arrangement it is seen that no ducting or baflling with cellulosic material is necessary inside the transformer housing or casing 12.

In the operation of the transformer the entire housing or casing 12 is usually filled with a cooling fluid such as oil or a suitable gas, with the exception of an air space at the top of the housing. It is seen from FIG. 1 that a plurality of coolers 70 is attached to the casing 12 on each side thereof near the top by means of a pipe 72 and near 44. The

the bottom by means of a pipe 74. These coolers permit the circulation of the cooling fluid from near the top of the casing 12 down through the coolers 70 in the direction indicated by the arrows thereon to the lower pipes 74 and from the lower pipes 74 into the main headers 46 where it is then forced through the openings 62 and 60 into the ducts 40 between the concentric windings 36 and 38 and up through the coils or windings 36 and 38 where it is again forced from the openings 50 in the upper distribution rings 48. This arrangement provides a positive and direct duct system for directing the cooling fluid from near the top of the transformer casing 12 back to the bottom of the casing and up through the space 40 between the concentric windings 36 and 38 and around the windings 36 and 38. This structure not only provides an eflicient cooling system for a core form transformer utilizing concentric windings, but also provides a system which is cheaper that the prior art systems since it is not necessary to provide bafliing with cellulosic material inside the transformer casing or housing 12 to obtain proper circulation of the cooling fluid to cool the transformer. If desired coolers of the type illustrated by the reference character 70 might also be attached to the end plates 64 to provide additional cooling of the fluid coolant.

The structure described herein also further permits more economical construction than the prior art since it is seen that the entire transformer may be assembled on the bottom wall .24 which has been positioned on top of the manifold members 46 and then the upper portion of the housing 12 may be lowered over the transformer and the flange 70 welded to the bottom wall 24 of the transformer with any suitable welding equipment.

FIG. 2 is a cross sectional view of a transformer utilizing the present invention. FIG. 2 may be considered as being taken along line IIlI of FIG. 1. The transformer in FIG. 2 is identical to that shown in FIG. 1, except that pumps P have been illustrated in the lower pipes 74 of the coolers70 for force circulating the cooling fluid from near the. 'top of the transformer casing 12 back to the manifolds 46 and up through the openings 40 between concentric windings 36 and 38. In all other respects the transformer illustrated in FIG. 2 is identical to that illustrated in'FIG. 1.

As pointed out hereinbefore, the transformer illustrated in FIGS. 1 and 2 provides an improved transformer wherein the lower frame members 46 for the lower yoke portion 34 of the core 30 also provides manifolds for receiving the cooled cooling fluid when it is returned from near the top'of the transformer casing 12 and positive duct means are provided for conducting this cooled cooling fluid from the manifold members 46 up through a fluid distribution ring 52 and up through the opening 40 between the concentric windings 36 and 38 to and around the windings 36 and 38 to cool the windings 36 and 38. This structure is also more economical to manufacture than the prior art structures, since no internal baffling is required inside of the casing or housing 12.

Although this invention has been described in connection with a three phase core form type transformer it is understood that it may be incorporated in any size or phase core form type transformer with the attendant advantages described.

While we have shown our invention in only one form it will be obvious to .those skilled in the art that it is not so limited, but is susceptible to various changes and modifications without departing from the spirit thereof.

We claim as our invention:

1. A transformer comprising a magnetic core having a winding leg, concentric windings on said winding leg, said concentric windings having a duct therebetween, a housing enclosing said core and said windings, said housing including a bottom wall for supporting said windings, manifold means below said bottom wall, fluid coolant in said housing for cooling said windings, means for conducting said fluid coolant from said housing to said manifold means, and means for directing said fluid coolant from said manifold means through said duct between said concentric windings.

2. The transformer as claimed in claim 1 wherein said manifold means provides a frame for said magnetic core.

3. The transformer as claimed in claim 1 wherein said manifold provides a support for said transformer.

4. The transformer as claimed in claim 1 wherein said means for directing said coolant fluid from said manifold means through said duct between said concentric windings comprises a fluid distribution ring for uniformly distributing the fluid between said concentric windings.

5. The transformer as claimed in claim 1 wherein said magnetic core has three winding legs with concentric windings on each said leg.

References Cited UNITED STATES PATENTS 3,137,829 6/1964 Dillow et a1 336-57 LARAMIE E. ASKIN, Primary Examiner.

A TONE, Assistant Examiner. 

1. S TRANSFORMER COMPRISING A MAGNETIC CORE HAVING A WINDING LEG, CONCENTRIC WINDINGS ON SAID WINDING LEG, SAID CONCENTRIC WINDINGS HAVING A DUCT THEREBETWEEN, A HOUSING ENCLOSING SAID CORE AND SAID WINDINGS, SAID HOUSING INCLUDING A BOTTOM WALL FOR SUPPORTING SAID WINDINGS, MANIFOLD MEANS BELOW SAID BOTTOM WALL, FLUID COOLANT IN SAID HOUSING FOR COOLING SAID WINDINGS, MEANS FOR CONDUCT- 